Interconnectedness and the Future of Ethernet

In mid-October, the Ethernet Alliance held its Technology Exploration Forum in Santa Clara, CA. For the first time in the event's history, TEF 2013 took place over two days. According to Ethernet Alliance chairman John D'Ambrosia, TEF 2013 brought together diverse voices in an effort to "leverage the brain trust of the industry."

TEF claims to set itself apart from other conferences through its focus on conversation. Unlike other conventions, in which speakers hold the floor for the majority of the time and leave little room for questions or interaction, D'Ambrosia said that at TEF, the speakers' role is to instigate and provoke. "It ends up being a consensus-building forum among all the different parties and perspectives," he explained. Discussions this year were lively, including at Ethernet co-inventor Bob Metcalfe's keynote: "The maestro performed for an hour and a half," D'Ambrosia said, and filled up a whiteboard with an array of topics for further exploration.

Whiteboard at Bob Metcalfe Keynote, TEF 2013

So what themes defined this year's discussion and, by extension, will influence research and development in times to come?

Vehicular Ethernet, the Internet of Things, and the Industry as an Ecosystem

One of the key themes D'Ambrosia stressed was the need for the industry to pull together and act as an ecosystem, since any given advance in one segment is bound to affect the rest of the networking world. To illustrate this, he pointed to developments happening in vehicular Ethernet, which he finds extremely exciting because of "the sheer ports that that will add to the Ethernet market." Considering how many millions of cars ship each year, he conservatively estimates that we will soon see 200 to 300 million additional ports per year of Ethernet connecting to networks.

"What happens when that gets integrated into the driving experience?" he asked. From enhanced traffic management and traffic alerts drawn from live video feeds broadcast from individual vehicles to the ability to tax cars based on their miles driven, the possible applications are endless. And have no doubt, those applications will be developed. D'Ambrosia cited Metcalfe's Law, which states that the value of the network increases as a function of the square of the number of people connected to it. Vehicular Ethernet will greatly increase the value of the network. The application developers are sure to follow.

And this is where the rest of the ecosystem comes in.

"People are talking about moving car-related functions into the cloud," he said. "It wasn't that long ago that the iPhone was crashing people's networks because they were using it so much. When you start thinking about what cars are going to do, what the potential is, it concerns me. I start cringing when I think about the bandwidth implications," D'Ambrosia added.

Vehicular Ethernet is just one example of a factor that D'Ambrosia anticipates will force change in the ecosystem. The Internet of Things itself, he said, is another. Even if individual devices' requirements are low, "because you have so many sensors, the aggregate effect could be huge," he pointed out. And speeds, feeds, and networks will all have to adjust to deal with that effect.

Standardizing software defined networking for interoperability

The industry as a whole must also pull together to ensure interoperability, D'Ambrosia told me, particularly when it comes to trends like software defined networking (SDN).

SDN was another key topic at TEF 2013, featured in two panels: one on how SDN will impact Ethernet and another on the challenges surrounding SDN standardization. The Ethernet community's interest in SDN mirrors that of the networking world, and "what SDN is going to mean for the community is very key," D'Ambrosia said.

When it comes to SDN, the key question for the Ethernet Alliance is what it will mean for the physical layer. "Are there 'hooks' that we need to put in at the physical layer to enable things?" he asked. Networks are growing, the numbers of servers—particularly virtual servers—rising, and virtualization of the network ramping up, all areas where SDN can help. But SDN still faces some challenges, particularly when it comes to interoperability. Here, D'Ambrosia told me, "the need for standardization is very key."

"In the past, people have talked about SDN more on an individual basis. But the Ethernet Alliance is supporting 802 in the standardization effort, which means we really want to be able to take Vendor A, plug it into Vendor B, plug that into Vendor C, and have it all work," he explained.

D'Ambrosia admitted that as a "physical layer guy," he isn't fully comfortable with discussing SDN except on that physical-layer level, but on that level, "it is very important to us to consider any new implications, new technologies, trends, or so on that could have an impact on development in 802" standards. And standardization efforts that result from, or are aided by, that consideration will have a positive effect on adoption of the trend as a whole.

"My biggest concern is that the worlds [of software and Ethernet] are a little separate, and we need to have more discussion that brings the SDN guys down to the question of what can we do with the physical layer to help you with SDN," D'Ambrosia said.

Next page: 40GbE and beyond and Energy Efficient Ethernet

40GbE and cost considerations

At a time when some enterprises are still looking at migrating to 10GbE, D'Ambrosia and the Ethernet Alliance are far ahead. D'Ambrosia himself is currently chairing the 400GbE study group. Discussion at TEF 2013 revolved mostly around 10, 40, and 100GbE, however, and the main concern was cost.

"We still need to bring costs down. Cost is an issue that never goes away," D'Ambrosia said. As an example, he said that "a lot of what we're seeing when it comes to 40GbE isn't really 40 gig. It's a 4 x 10 used in a high-density mode for 10GbE, if you will, and that's a cost issue." To him, the main challenge moving forward is the need for solutions that ultimately drive costs down. It's almost a given that feeds and speeds must increase, he said—some people are already talking to him about terabit Ethernet—but cost creates an additional pressure to address.

With that being said, however, new developments are emerging. The Ethernet Alliance is now talking about 100 Gigabit Ethernet on a single lambda via a modulation, he told me, to achieve "higher effective data rates."

"When we look at an ecosystem perspective, we're looking at a new ecosystem developing that is based not on 10 Gigabit Ethernet, but on 100GbE," he said. And this isn't a simple decision to make or implement. The decision to move to 100GbE is so crucial that it must involve the entire industry, he told me, and must include careful discussion of the economics of the technology. In fact, the Ethernet Alliance is working with the Optical Society of America (OSA) to sponsor a workshop for further discussion on the topic.

Energy Efficient Ethernet

As networks grow and evolve, their power consumption may rise, creating additional cost issues. The Energy Efficient Ethernet (EEE) standard for twisted pair and backplane Ethernet aims to counter that by reducing power consumption as activity drops. D'Ambrosia has watched EEE develop over the years, until now, with the 400GbE project, "it is recognized as important and crucial to design."

D'Ambrosia called EEE an "apple-pie objective": its necessity is universally accepted, and no one argues against that. The Ethernet Alliance is now working on adding it to optical transport networking as well as copper, since the cost consideration makes it an increasingly important subject.

"It comes down to cost in my mind. If I can use less energy and save more dollars, that's what I'm going to do," he said. He added that "EEE is a very powerful tool that Ethernet now provides and will be providing in all technologies from copper 10GbE and up, and in the base-Ts, it goes down to even the lower speeds."

Interconnectedness and the importance of consensus-building

Addressing both the main themes D'Ambrosia mentioned—interoperability and cost concerns—will require a general consensus and interconnectedness among diverse segments of the networking community. Other TEF 2013 panels bear this out, from the panel session that pulled leaders from 802.1, 802.3, and 802.11 up onto a stage with the chair of 802, to sessions that focused on the synergy between wired and wireless technologies and on photonic integration.

"We're talking about stuff that affects the ecosystem. It's all becoming more and more interconnected, and you see that through the topics and discussions being brought up," he said.

Is it a lot to think about? Yes, but D'Ambrosia professes to love it, especially at this point in time.

"If you enjoy what you're doing, you never work a day in your life. I'm tired, and I'm busy, but I'm really enjoying myself right now," he said.